In order to patch successfully, you must delete the following files from inside your World of Warcraft folder:http://us.battle.net/support/en/article/64bit-client-prevents-patching-to-433
World of Warcraft-64.app (Mac)
We apologize for any inconvenience this issue may cause, but please be aware that since the 64-bit client is still in a testing state that complications such as this may happen from time to time. Thank you.
A updated version of the client will be released soon.